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  1. Jan 21, 2022
    • Miaoqian Lin's avatar
      parisc: pdc_stable: Fix memory leak in pdcs_register_pathentries · d24846a4
      Miaoqian Lin authored 
      kobject_init_and_add() takes reference even when it fails.
According to the doc of kobject_init_and_add()：

   If this function returns an error, kobject_put() must be called to
   properly clean up the memory associated with the object.

Fix memory leak by calling kobject_put().

Fixes: 73f368cf

 ("Kobject: change drivers/parisc/pdc_stable.c to use kobject_init_and_add")
Signed-off-by: default avatarMiaoqian Lin <linmq006@gmail.com>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
      d24846a4
    • Jason Gerecke's avatar
      HID: wacom: Avoid using stale array indicies to read contact count · 20f3cf5f
      Jason Gerecke authored 
      If we ever see a touch report with contact count data we initialize
several variables used to read the contact count in the pre-report
phase. These variables are never reset if we process a report which
doesn't contain a contact count, however. This can cause the pre-
report function to trigger a read of arbitrary memory (e.g. NULL
if we're lucky) and potentially crash the driver.

This commit restores resetting of the variables back to default
"none" values that were used prior to the commit mentioned
below.

Link: https://github.com/linuxwacom/input-wacom/issues/276
Fixes: 003f50ab

 (HID: wacom: Update last_slot_field during pre_report phase)
CC: stable@vger.kernel.org
Signed-off-by: default avatarJason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: default avatarPing Cheng <ping.cheng@wacom.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      20f3cf5f
    • Jason Gerecke's avatar
      HID: wacom: Ignore the confidence flag when a touch is removed · df03e9bd
      Jason Gerecke authored 
      AES hardware may internally re-classify a contact that it thought was
intentional as a palm. Intentional contacts are reported as "down" with
the confidence bit set. When this re-classification occurs, however, the
state transitions to "up" with the confidence bit cleared. This kind of
transition appears to be legal according to Microsoft docs, but we do
not handle it correctly. Because the confidence bit is clear, we don't
call `wacom_wac_finger_slot` and update userspace. This causes hung
touches that confuse userspace and interfere with pen arbitration.

This commit adds a special case to ignore the confidence flag if a contact
is reported as removed. This ensures we do not leave a hung touch if one
of these re-classification events occured. Ideally we'd have some way to
also let userspace know that the touch has been re-classified as a palm
and needs to be canceled, but that's not possible right now :)

Link: https://github.com/linuxwacom/input-wacom/issues/288
Fixes: 7fb0413b

 (HID: wacom: Use "Confidence" flag to prevent reporting invalid contacts)
CC: stable@vger.kernel.org
Signed-off-by: default avatarJason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: default avatarPing Cheng <ping.cheng@wacom.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      df03e9bd
    • Jason Gerecke's avatar
      HID: wacom: Reset expected and received contact counts at the same time · 546e41ac
      Jason Gerecke authored 
      These two values go hand-in-hand and must be valid for the driver to
behave correctly. We are currently lazy about updating the values and
rely on the "expected" code flow to take care of making sure they're
valid at the point they're needed. The "expected" flow changed somewhat
with commit f8b6a747 ("HID: wacom: generic: Support multiple tools
per report"), however. This led to problems with the DTH-2452 due (in
part) to *all* contacts being fully processed -- even those past the
expected contact count. Specifically, the received count gets reset to
0 once all expected fingers are processed, but not the expected count.
The rest of the contacts in the report are then *also* processed since
now the driver thinks we've only processed 0 of N expected contacts.

Later commits such as 7fb0413b (HID: wacom: Use "Confidence" flag to
prevent reporting invalid contacts) worked around the DTH-2452 issue by
skipping the invalid contacts at the end of the report, but this is not
a complete fix. The confidence flag cannot be relied on when a contact
is removed (see the following patch), and dealing with that condition
re-introduces the DTH-2452 issue unless we also address this contact
count laziness. By resetting expected and received counts at the same
time we ensure the driver understands that there are 0 more contacts
expected in the report. Similarly, we also make sure to reset the
received count if for some reason we're out of sync in the pre-report
phase.

Link: https://github.com/linuxwacom/input-wacom/issues/288
Fixes: f8b6a747

 ("HID: wacom: generic: Support multiple tools per report")
CC: stable@vger.kernel.org
Signed-off-by: default avatarJason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: default avatarPing Cheng <ping.cheng@wacom.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      546e41ac
  3. Jan 20, 2022
  5. Jan 19, 2022
  7. Jan 18, 2022

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